Pradeepak R.,Automotive CAE |
Bhambri M.,Automotive CAE |
Rahman S.,Mahindra Two Wheelers Ltd.
SAE Technical Papers | Year: 2015
This paper describes about handling validation of a motorcycle on a steady state condition. Nowadays, it is very usual and common to get a feedback by motorcycle test riders that the steering feel is heavy due to which more effort is required to complete a full track circuit. So it has become a necessity to focus the study on handling dynamics of motorcycle at the initial stage itself using a numerical tool. To decide the handling characteristics it is very important to focus on the steering effort required at the handle bar by the rider, as it is the main control to study the 'out of plane' dynamics. To test the vehicle for steering performance, track radius and velocity were chosen as the variables to avoid the transient behavior and identify the key parameters at a faster rate. To study & investigate the steering effort influencing factors, an MBD numerical tool helped to solve the problem. A validated motorcycle model with parametric approach was developed to quickly determine the contributors of steering effort. Optimized variables ensure that the rider applies less effort to the handle bar and thus to control the motorcycle. This paper discusses the robust MBD model which ensures directional stability of motorcycle without much compromise on handling. The objectives met had a very good agreement with subjective evaluation on proving grounds. Copyright © 2015 SAE International. Source
Pradeepak R.,Automotive CAE |
Kumbhar S.,Mahindra Two Wheelers Ltd.
SAE Technical Papers | Year: 2016
At present, vehicle testing in laboratory is one of the important phase to quicken the product validation process. In the early phase of laboratory testing it is required to evaluate the strength of the vehicle structure through physical rig setup which represents the consumer's usage. Two and Multiple poster input excitation are among the laboratory rig testing to represent the actual road are used to predict the durability of vehicle components. The road inputs through the poster are known as drive files, a feedback controlled system which reproduces the track or real road recorded specimen's accelerations, displacements and strains in laboratory. Derivation of drive files in poster testing requires iteration of physical specimen to exactly replicate the actual road. This paper discusses about generation of drive files as inputs for poster actuation with virtual model(as a substitute for actual model)which is applicable in areas of vehicle durability and ride comfort studies. For the reason to minimize the time,cost,man-machine hours and energy, an automation is developed to simulate the validated virtual model with iterations process to generate the road files for further use in physical and virtual test.The paper details on the procedure followed traditionally and what changes have been made in the current process to generate road drive input files. © Copyright 2016 SAE International. Source
Jain A.,Mahindra Two Wheelers Ltd.
SAE Technical Papers | Year: 2015
Conventional motorcycle swingarm design includes steel tubing and sheet metal structures. Conventional swingarm are inherently over-designed as their design comprises of tubular structures of same cross section through the entire length of the swingarm, whereas the stress induced varies along the length (maximum near the frame pivot). An aluminum alloy swingarm design even when subjected to casting manufacturing constraints, has the potential for better material layout and weight minimization. But obtaining an ideal material layout for maximum performance can be a challenge as it requires a number of time consuming design iteration cycles. This paper aims to use concept based design methodology for design of aluminum alloy swing arm by application of topology optimization techniques to meet styling and structural targets and thus, obtain an end user product. This paper demonstrates the use of a concept based design approach in contrast to the conventional experience based approach. The concept based designing can be deemed to be more profitable and as it greatly reduces design iteration cycle time. Copyright © 2015 SAE International. Source
Ganesan A.,Mahindra Two Wheelers Ltd. |
Sundaram S.,Mahindra Two Wheelers Ltd.
SAE Technical Papers | Year: 2012
State of Charge (SOC) of a storage battery gives the capacity remaining in the battery to meet the load demands. SOC of a Lead Acid battery is predicted based on the temperature compensated value of electrolytes' specific gravity (Sp. gr.). Since measuring specific gravity is not possible in an automobile under dynamic conditions, Open Circuit Voltage (OCV) is used as the parameter to predict the SOC. But OCV can indicate SOC accurately only after a sufficient period of rest of a battery in any condition. Also it varies between batteries due to several factors like temperature, ageing, electrolyte volume, internal construction, etc. Predicting the SOC of battery theoretically depends on number of equations developed to accommodate these variables. Hence for a real time estimation of SOC of battery, a Heuristic algorithm is suggested. The initial State of Battery is estimated by temperature compensated OCV Vs SOC characteristics and followed by dynamic prediction of SOC using Coulomb or Energy Measurement. The drawback of cumulative error in energy measurement is also overcome in this algorithm. For improving the accuracy of dynamic prediction, the heuristic algorithm also talks about compensating the predicted SOC value with respect to factors such as rate of discharge, rate of charge, self discharge and temperature. Finally, the algorithm also talks about "A Self learning feature", to predict OCV based the initial SOC of Lead Acid battery more accurately irrespective of the vehicle quiescent current differences. Copyright © 2012 SAE International. Source
Khan S.A.,Mahindra Two Wheelers Ltd. |
Dhongde S.,Mahindra Two Wheelers Ltd.
SAE Technical Papers | Year: 2014
A small single cylinder 4 stroke gasoline engine varying capacity from 100cc to 500cc generally used for two wheelers has a wide range of load conditions. Such variation in load on engine demands variation in Transmission ratio at different vehicle speeds for optimum performance, drivability and Economy. A scooter has continuously variable transmission called as CVT which is generally centrifugally controlled with respect to engine speed as against that of series of manual gears used in motor cycle. The work aims at creating a mathematical model for controlling variation in transmission ratio of CVT by converting the generally centrifugally controlled CVT by electronic control. The objective is to implement the mathematical model with a novel electronic controlled CVT in a two wheeler engine for the improvement in performance. The mathematical model done through geometric calculations and modeling is discussed in details. The mathematical model is compared with the actual testing data to validate the calculations and results. Thus with this mathematical model and mechanism we can achieve a variation in engine transmission ratio as per load demand. The work explains the impact of mathematical model for controlling CVT ratio installed on the two wheeler engine and hence will resultant improvement in performance in terms of drivability and economy of a vehicle. On the whole it concludes that this mathematical model can be implemented on small engines for better performance. Copyright © 2014 SAE International. Source